Best there is

You think of music making apps and you think of blocky, Hard to follow, Low quality apps. But this is by far the best. I can use this for hours and not get bored, They produce good quality sounds that can pass as studio produced. They release a new pack every week of a different genre and $2 is definitely worth it

JesseSchenk about Launchpad - Music & Beat Maker, v5.2